Deep-rooted and bitter ill feeling; resentment or animosity, esp. of long standing; an instance of this.

The quality or state of being bitter. animosity, acrimony of temper, action, or words.

bitter feeling.

Bitter feelings or sentiments; acrimony; resentment; (also) the quality of being bitter to the mind or feelings; distress; anguish. Somewhat rare…

Gall, bitterness; (hence) animosity, rancour.

Scottish. Bitter malice; rancour; an instance of this. Obsolete.

Also more fully bitter aloe(s). figurative. Bitter experiences, occurrences, etc.; bitterness. Usually in plural (with singular agreement).

In various senses relating to disposition or state of feeling. Anger, irritation; malice, ill-will, spite; vexation, pique. Obsolete.

bitter anger.

= virulence, n. 1.

figurative referring to its bitterness.

Bitterness; the quality of being like nitre, esp. in respect of its bitterness.

The action of embittering; the state of being embittered.

Extreme acrimony or bitterness of temper or speech; violent malignity or rancour.

Acrimony, exasperated condition. Obsolete.

Virulence.

Embitterment; a feeling of bitterness. Also: exacerbation of a negative feeling or problem. Cf. acerbate, v.